Breaking Changes:

Rwfus now stores overlays inside a disk image
- This fixes #12, #13
Default Base Directory changed to /opt/rwfus
Configuration file pared down to just the bare minimum options
- Extended configuration is still available, but is now mostly derived from Base_Directory, Systemd_Directory, and Mount_Options (new!)
New extended configuration options to do with disk images:

Option	Description	Default Value
`Disk_Image`	Full path to disk image file	`/opt/rwfus/rwfus.btrfs`
`Mount_Directory`	Location which the disk image is mounted into	`/opt/rwfus/mount`
`Mount_Options`	Mount options, with which to mount the disk image	`loop,compress`

New features:

Now works on reimaged Steam Decks!
Due to btrfs compression, overlays now take up less space on disk!
Installation will automatically set up pacman if successful
Now keeps track of whether SteamOS Offload: /usr/local is enabled, and, if so, preserves that path after mounting